Railway signaling.



H. W. GRIFFIN.

RAILWAY SIGNALING.

APPLlcATloN FILED JUNE 3o. 1913. RENEwED ocT. 13,19l6.

1,21 1,142. Patented Jan. 2, 19W.

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ITNEssE MMM H. W. GRIFFlN.

RAILWAY SIGNALING.

APPLICATION FILED 1uNE3o. 1913. aENEwED ocr. 13.1916.

1,21 1,142., Patented Jan.2,1917.

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H. W. GRIFFIN. RAILWAY SIGNALING.

APPLICATION FILED IUNE 30, |913. RENEWED OCT. I3. yI9I6.

1,21 1,142, Patnted Jan. 2, 1917.

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RAILWAY slGN/ILING. APPLICATION FILED )UNE 30, IV9I3. RENEWED'OCT. 13.1916.

R O T N E V m Patented Jan. 2, 1917.

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HENRY W. GRIFFIN, 0F NEW YORK, N. Y., ASSIGNR T0 THE UNION SWITCH L SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA. A

COBRATIGN 0F PENNSYLVANIA.

RAILWAY SIGNALING.

Continuation in part of application Serial No.

Patented J an. 2, 19112.

This application filed June 30, 1913, Serial No. 776,482. Renewed October 13, 1916. Serial No. 125,502.

Z o @ZZ whom t may concern Be it known that I, HENRY TN. GRIFFIN, a citizen of the United States, residing at N ew York, in the county of New York, and State of New York, have invented certain new and useful Improvements in Railway Signaling, of which the following is a specification.

My invention relates to railway signaling, and particularly to signaling for stretches of single track over which traffic moves in both directions, such for example as stretches of single track between passing sidings.

I will describe two forms of railway signaling embodying my invention and will then point out the novel features thereof in claims.

The present application is a continuation of my application filed January 27, 1913, Serial No. Mel-,367, for railway signaling.

In the accompanying drawings, Figure 1 is a diagrammatic view showing a stretch of single track having applied thereto one arrangement of apparatus and circuits embodying my invention. Figs. 2, 3 and 4l are 'iews similar to Fig. 1 but showing the operation of the apparatus during the passage of a car or train through the stretch.

Similar reference characters refer to similar parts in each of the several views.

Referring to the drawings, the reference character A designates the track rails of a stretch of railway track over which traffic moves in both directions The track rails of the stretch A are electrically separated from 'the adjoining track rails by insulations Q9. The stretch A is provided with a track circuit comprising the track rails, a source of current connectedr with the track rails adjacent the middle of the stretch and two track relays R and It, connected with the track rails adjacent the ends of the stretch respectively. As here shown, the source of current for the track circuit is a secondary winding 1 of the transformer T, whose primary 2 is supplied with alternating signaling current from a suitable source, not shown in the drawings. Since the signaling current is alternating in character, the track relays R and R are preferably of a type responsive only to alternating current; as here shown, they are of the vane type. When a track circuit is arranged as just described, that is, with the source of signaling current adjacent the middle, and a relay adjacent each end, it is well understood that when a car or train enters the stretch from either' end, it immediately opens the relay adjacent the entering end, but the relay adjacent the other end is not opened until the car or train reaches a point near the point of connection of thesource of current with the track rails, as indicated on the drawings. After the car or train has passed a short distance beyond the point of connection of the source of current with the rails, the relay first opened again closes, but the other relay remains open until the car or train leaves the stretch. The point at which the relay first Opened closes is substantially the same as the point at which a car or train moving in the opposite direction causes this relay to open.

Trafiic into the stretch A is governed by two end signals S and S', located respectively adjacent the ends of the stretch. Traffic through the stretch is also governed by'two intermediate signals B and B; signal B is located in advance of signal S, hut opposite to or in the rear of the point at which an eastbound oar or train causes relay l to open, and signal B is located in advance of signal S, but opposite to or in the rear of the point at which a westbound ear or train causes track relay R to open. lach of the four signals is adapted to indicate stop and proceed, as here shown, all four of the signals are of the semaphore type, 1out it is understood that other types of signals may equally well he employed.

The signals are provided with circuits which are controlled by relays R and R, and which are supplied with alternating current hy a secondary .7 of transformer T and also by the secondaries of transformers T and T2, the primaries of these latter transformers being also energized from the source of alternating signaling current. For convenience, I have indicated by plus and minus signs the instantaneous polarities of the secondary 7 and of the secondaries of transformers T and T2. The circuit for signal B is from the positive side of the secondary of transformer T2, through wire 3, contact l of relay R', wire 5, signal B, wire 6, common wire 0, to the negative side of the secondary oftransformer T2. Similarly Yso g Y Y 1,211,142

the circuitV for signal B is from the positive side of transformer T', through Wire 8, Contact' 9 of relay R, Wire 10, signal B', Wire 11, common Wire vto negative side of transformer T. Operatively connected with signal B are three contacts, 12, 13 and 14, and operatively connected with signal B" are three contacts 12a, 13a, and 14a. As-here shown, the circuit for signal S is controlled by contact 12 operated by -signals B, the circuit for signal being from the positive side of secondary 7 through Wires 15, 16 and 17, contact 12, wires 18 and 19, contact 20 of relay R, Wire 21, signal S, common Wire 0 to negative side of secondary 7. Signal S' issiinilarly controlled by contact 12a of signal B', the circuit for signal S' being from the positive side of secondary 7 through Wires 15, 22, 23 and 24, contact 12, Wires 25 and 26, contact 27, Wire 2S, signal S, common Wire 0 to negative side of secondary 7.

To describe the control of the signals more briefly; signal B is controlled-only by relay R; and signal S is controlled by signal B and Valso by relaycR, hence signal S is in effect controlled -by relays VR and R'. Similarly, signal B is controlled only by relay R, and signal Svis controlled by signal B' and by relay B', so that signal S is in effect controlled by relays R and R'.

It is evident that with the circuits thus far described, When an eastbound car or train passes through the stretch, signal S would indicate stop until the car or train leavesV the stretch, this signal being held at stop first by relay R and later by contact 12, which in turn is held open because signal B is held at stop by track relay R'. For similai` reasonssignal S Would be held at stopy throughout thejpassage of a Westbound cai' or train through the entire stretch. It some-Y times is desirable, however, that after a. car or train has passed some distance into the stretch A, a following car or train should be Vpermitted to enter the stretch. For this reason 1 provide means for permitting the end signal S or S'V in the rear of a car or train to change to proceed indication after such car or train has passed some distance into the stretch. I will now explain the means here shown by which this control of the end signals is accomplished.

The circuit for end signal S is Vprovided With a shunt around contact 12 and this shunt is opened and closed by an auxiliary relay X. This shunt is from Wire 16, throughvvire 30, contact 31 of relay X, Wire 32 towire 19. Similarly, the control circuit for signal S is provided with a shunt around the contact 12, and this shunt is opened and closed by an auxiliary relaycX'. The shunt for this latter circuit is from Wire 22, through Wire 33, contact 34 of relay X', Wire 35-to Wire 26, VEach of these auxiliary relays is provided with a pick-up circuit and a holding circuit, Which circuits are controlled by the contacts operated byY thesignals B and B. The pick-up circuit for auxiliary i'elayjX is from the positive side vof secondary '7, through Wires 15, 16 and 17,

contact 14, Wire 36, back contact 37v of relay X, Wire 38, contact 13, Wire39, relay X',

Wires 40 and 1-1, common Wire O tosecond-` and when auxiliary relay X is open. Y The vholding circuit for auxiliary relay X is from positive side of transformer 7 through Wires 15, 22, 23 and 41,co-ntact 42 of relay X wire 43 contact 132L Wire 39 rela XV Y' Wires 40- and 11 and common Wire 0 of secondary 7. This circuit is indicated by heavy lines in F ig.r 3. 1t will be seen that this holding circuit can be closed only when relay X is closed and signal B indicates stop. The pick-up and holding circuits for relay X are similar to those just traced for relay X', hence they need not be traced herein.

The operation of the apparatus'is as follows: Referring particularly to Fig. 2, when aV Westbound car or train Wv enters the stretch A, it first opens track relay R', thereby causing signals S and B to changeto stop indication and the operation of signal B opens the circuit of signal S, Which therefore also ychanges to stop indication. The operation of signal B closes contact 14 there- Vby closing the pick-up circuit of auxiliary relay X so that this relay then becomes en- Y ergized This pick-up circuit is indicated in Fig. 2 by heavier lines than the other cirsuits. Referring now to Fig. 3, when the car or train-.1l reaches a point near-fthe middle of the stretch itcauses trackrelay R to open and this relay opens the circuit of intermediate signal B" which latter then This operation of signal B closes contact 13a and since aux- Y changes to stop indication.

train Vif reaches a'point beyond the middle l of the stretch it allo-Ws track relay R to close and the control circuit for signal S is then closedv through the shunt controlled by auxiliary relay X.V for signal S is VnoivY Yas indicated in the The controll circuitV heavier lines in Fig. 4, andfis as follows:

from, the positive side of secondary r7 through Wires 15, 22 and 33, contact 34 of iso iio

relay X, wires 35 and Q6, contact 27 of relay R, wire 28, signal S, common wire 0 to negative side of secondary 7. Signal S therefore now indicates proceed, so that a following westbound car or train may enter the stretch A. lf the car or train W leaves the stretch A before the following car or train reaches signal B this latter signal will have changed to proceed indication so that the following car or train may then proceed through the remainder of the stretch A. 1f, however, the car or train W has not left the stretch A by the time the following car or train reaches signal B, this latter signal will continue to indicate stop and the following car or train must be brought to a stop and must wait until the car or train W leaves the stretch.

The operation of the apparatus during the passage of an eastbound car or train through the stretch A is similar to that which I have just described for a westbound car or train, hence it need not be explained herein. v

Each of the auxiliary relays X and X is preferably of a slow-acting type in order to avoid any tendency to open while the relay is being transferred from its pick-up circuit to its holding circuit by contact 13 or 13a, However, if contacts 13 and 18a are so constructed that the movable member engages with one contact point before leaving the other point, then the auxiliary relay is not denergized during the change, and the slow-acting feature of these relays is not absolutely essential.

If two cars or trains moving in opposite directions should enter the stretch A simultaneously, both would find the end signal indicating proceed, and both c ars or trains would therefore be authorized to proceed into the stretch at full speed. As soon as these cars or trains enter the stretch however, signals B and B would both change to stop indication, hence both cars or trains would be brought to a stop and a collision would be prevented. Signals B and B should, of course, be located far enough apart to enable both cars or trains to be brought to a full stop before colliding, even if both were proceeding at full speed while passing signals B and B; in other words, the distance between signals B and 4B should be equal to or greater than twice the maXimum braking distance of the rolling stock.

One feature of railway signaling embodying my invention is the provision of means for permitting two cars or trains proceeding in the same direction to occupy a stretch of track at the same time, both being protected by absolute signals, only a single track circuit being necessary for the entire stretch.

Although l have herein shown and described only one form of railway signaling embodying my invention, 'it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention,what l claim is:

l. ln combination, a stretch of railway track over which traffic moves in both directions, two track relays one connected with the track rails adjacent each end of the stretch, a source of signaling current connected with the track rails at a point between said relays, two end signals located respectively adjacent the ends o-f the stretch, wo intermediate signals located respectively on opposite sides of the point of connection of the source of current with the rails, means for controlling each intermediate signal by the track relay on the opposite side of said source and for controlling each end signal by both track relays, and means for each end signal controlled by the intermediate signals for rendering the first-mentioned means ineffective so far as the control of said end signal by the track relay at the opposite end of the stretch is concerned.

2. In combination, a stretch of railway track, two track relays one connected with the track rails adjacent each end of the stretch, a source of alternating signaling J current connected with the track rails at a point between said relays, two end signals located respectively adjacent the ends of the stretch, two intermediate signals located respectively on opposite sides of the point of connection of the source of current with the rails, means for controlling each intermediate signal by the track relay on the opposite side of the said source of current and for controlling each end signal by both track relays, and means for each end signal for rendering the first-mentioned means ineffective so far as the control of said end signal by the track relay at the opposite end of the stretch is concerned.

3. In combination, a stretch of railway track, two track relays connected with the rails of the stretch adjacent the ends thereof, a source of signaling current connected with the rails between said relays, two end signals located respectively adjacent the ends of the stretch, two intermediate signals located respectively on opposite sides of the point of connection of said source with the rails and each intermediate signal being located at the point at which a car or train passing through the stretch from the adjacent end opens the track relay at the other end or farther from the source than said point, means for controlling each intermediate signal by the track relay on the opposite side of said source and for controlling each end signal by both track relays, and means for each end signal for rendering the first-mentioned means ineffective so far as respectively and arranged to be opened successively by a car or train passing through the stretch, the relay first opened remaining open until after theother relay has opened,

means associated with the track rails be-Y tween said relays ttor energizing said relays, two end signals located respectively adjacent the ends of the stretch, two intermediate signals located respectively on opposite sides of said energizing means, each intermediate signal being located at' the point at which a car or train passing through the stretch :trom the adjacent end opens the track relay at the other end or farther from the energizing means than said point, means for controlling each intermediate signal by the relay on the opposite side of said energizing means and for controlling each end signal by both relays, and means tor each end signal for at times removing therefrom the control Vnormally exerted thereon by the track relay at the other end of the stretch.

5. In combination, a stretch of railway track, two track relays connected with the track rails adjacent the ends of the stretch respectively and arranged to be opened successively by a car or train passing through the stretch, the relay iirst opened remaining open until after the other relay has opened, means associated with the trackrails between said relays for energizing said relays, two end signals located respectively adjacent the ends of the stretch, two intermediate signals located respectively on opposite sides of said energizing means, each intermediate signal being opposite the point at.

which a car or train passing through the stretch from the yadjacent end causes the track relay at the opposite end to open or Y farther from the energizing means than said point, means for controlling each intermediate signal by the track relay at the opposite end of the stretch and for controlling Veach end signal by both track relays, means comprising an auxiliary relay for each end signal for rendering the iirst-mentioned controlling means ineiective so far as the control of said end signal by the track relay at the opposite end of the stretch is concerned, and` means for controlling said auxiliary relays.

6. In combination, a stretch of railway track, two track relays connected with the vtrack rails adjacent the endsv of the stretch respectively and arranged to be opened successively by a car or train passing through the stretch, the relay irst opened remaining open until after the other relay has opened,

`means associated with the track railsbetween said relays for energizing said relays, two end signals located.v respectively adjacent the ends of the stretch, two intermediate signals located: respectively on opposite sides of said energizing means, each intermediate signal being' located opposite thev point at which a car or train passing through the stretch from the adjacent end causes the track relay at the opposite end to open, or farther from the energizing means than said point, a signal circuit for each intermediate signal which circuit is controlled cates proceed or stop, a signal circuit for each end signal which circuit is controlledV by the circuit controller for the adjacent intermediate signal, a shunt for each end signal circuit around the circuit controller .for that circuit, an auxiliary relay for closing each shunt, and means controlled by said intermediate signals for iliary rela-ys.

7. In combination, a stretch of railway track, two track relays connectedwith the track rails-adjacent the ends of the stretch respectively and arranged to-be opened successively bya car or train passing through the stretch, thev track relay first opened remaining open Vuntil after the other track relay has opened, means associated with the track railsbetween said relays for energizing said track relays, two end signals located respectively adjacent the ends of the stretch, two intermediate signals located respectively on opposite sides of said energizing means, each intermediate signal being located opposite the point at which a car or train passing through the Astretch from the adjacent end causes the track relay at the oppositeend to open, or farther from the energizing means than said point, a signal circuit for each intermediate signal which circuit is controlled'by the track relay at the opposite end of the stretch, a circuitV controller operated by Veach intermediate signal and arranged to be closed 0r open according as the signal indicates proceed or stop, a signal circuit for each endV signal which circuit is controlled by the circuit controller for the adjacent intermediate signal, a Vshunt for each vend signal circuit around the circuit controllerfor'that circuit, an auxiliary relay for closing each shunt, a second circuit controller operated by each intermediate signal vand arranged to be closed or open according'as the signa-l closing said aux- Y signal adjacent the other end of the stretch. i

8. In combination, a stretchV of railwayV track, two `track relays connected with the c r'n'O' Ya. ail m 'i "'av nie gi/ing me ns, e cl inter edlate sign l being opposite the point at which a car or train passing through the stretch from the adjacent end causes the track relay at the opposite end to open, or farther. from the energizing means than said point, a signal circuit for each intermediate' signal Which circuit is controlled by the tra-ck relay at the opposite end of the stretch, a circuit controller operated by each intermediate signal and arranged to be closed or open according` as the signal indicates proceed or stop, a signal circuit for each end signal Which circuit is controlled by the Circuit controller for the adjacent intermediate signal, a shunt for each end signal circuit around the circuit controller for that circuit, an auxiliary relay for closing each shunt, a pick-up and a holding circuit for eacli auxiliary relay; and contacts and conductors controlled by the intermediate signals for closing the pick-up circuit of an auxiliary relay when the adjacent intermediate signal indicates proceed and the other intermediate signal indicates stop7 and for closing the holding circuit when the auxiliary relay is closed and the adjacent intermediate signal indicates stop.

ln testimony whereof l aiiix my signature in presence of two Witnesses.

HENRY W. GRIFFIN. Witnesses:

A. M. LINDENs'rnU'rH, Rona'. B. KAY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of atents, Washington, D. C. 

